Shape-tuning the colloidal assemblies in nematic liquid crystals
Shape-tuning the colloidal assemblies in nematic liquid crystals
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DOI：
10.1039/c2sm06577k
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发表时间：
2012-01-01
期刊：
影响因子：
3.4
通讯作者：
Zumer, Slobodan
中科院分区：
文献类型：
--
作者：
Dontabhaktuni, Jayasri;Ravnik, Miha;Zumer, Slobodan
胶体片晶是二维周期性晶格形状控制组装的天然构建块，并且可以形成多功能光学元件。使用三维（3D）的数值模拟，我们证明了自组装的三角形，正方形和五边形亚微米尺寸的血小板在一个薄层的液晶。作用于单个血小板的扭矩计算，显示与四极对称（正方形，六边形等）的血小板，取向，更强烈地约束比血小板与偶极对称（三角形，五边形），这是重要的开关应用。血小板间的潜力取决于在一个复杂的方式对血小板的取向，表现出容易和困难的重定向轴和多个极小值。弹性偶极子的线性链通过有趣的旋转和平移位移形成二维周期性晶格，以最大限度地减少周围介质的扭曲。
Colloidal platelets are natural building blocks for the shape-controlled assembly of two-dimensional periodic lattices and can form versatile optical elements. Using three-dimensional (3D) numerical modelling, we demonstrate the self-assembly of triangular, square and pentagonal sub-micrometer sized platelets in a thin layer of nematic liquid crystal. Torques acting on individual platelets are calculated, showing that platelets with quadrupolar symmetry (squares, hexagons, etc) are, orientationally, more strongly bound than platelets with dipolar symmetry (triangles, pentagons) which is important for switching applications. Inter-platelet potentials are shown to depend in a complex way on the orientations of the platelets, exhibiting easy and hard reorientation axes and multiple minima. Linear chains of elastic dipoles form into two-dimensional periodic lattices via interesting rotational and translational shifts, to minimize the distortions in the surrounding nematic medium.